Three-dimensional printer



FIG. 1 is a front view of a three-dimensional printer showing the new design;

FIG. 2 is a top-front perspective view thereof;

FIG. 3 is a front, left side perspective view thereof;

FIG. 4 is a view of the left side thereof, the right side being a mirror image thereof;

FIG. 5 is a back view thereof;

FIG. 6 is a top view thereof; and,

FIG. 7 is a bottom view thereof.

The broken lines showing portions of the three-dimensional printer form no part of the claimed design. 

CLAIM The ornamental design for a three-dimensional printer, as shown and described. 